More than 100,000 Libya refugees have flooded Tunisia and Egypt, the U.N. says. Meanwhile, the EU places a weapons embargo on Moammar Kadafi's regime, and the U.S. freezes assets.

Reporting from Tripoli, Libya — Moammar Kadafi's loyalists appeared to have strengthened their grip on the Libyan capital, while chaos roiled much of the country and spilled over its borders in a wave of frightened refugees.

The unrest in Libya has left hundreds dead and nearly frozen the country's oil-based economy. The United Nations reported Monday that more than 100,000 refugees, many of them laborers from nearby countries, have fled to Tunisia and Egypt over the last week to escape destitution and an outbreak of violence that has drawn international condemnation.

European countries, which have invested heavily in Libya in recent years, were dramatically scaling back their ties. The European Union imposed a weapons embargo and banned 26 people, including Kadafi, from entering.

U.S. officials said they had frozen more than $30 billion in Libyan assets, the largest such action carried out by the U.S. government. A U.S. warship carrying 1,000 Marines was being sent to the Mediterranean Sea, but Pentagon officials said they would go ashore in Libya only as part of a humanitarian mission.

Opponents of Kadafi who have seized control of eastern cities claimed Monday to be inching closer to the key northwestern corridor from Tripoli, the capital, to the Tunisian border. Government supporters hotly denied that.

Rebels in the city of Misurata, about 120 miles east of Tripoli, reportedly shot down a government plane and pushed back an effort to retake the city. In Zawiya, about 30 miles west of Tripoli, government forces surrounded rebels but had not forced them to retreat.

In the east, a warplane fired at least one missile at a military armory a few miles from the rebel-held city of Ajdabiya, residents said, and one or two other missiles struck a nearby village. Military officials and residents said the missile fired at the armory did not hit any of the more than a dozen buildings filled with weapons.

Kadafi's son, Seif Islam, predicted in an interview Monday night that forces loyal to his father would reassert control over rebellious parts of the country.

"Everything is going to be OK in the next few days," the Western-educated 38-year-old said. "Thousands of people are calling me every day and saying: 'Please, come. Restore peace and order.' "

Revolutions in neighboring Tunisia and Egypt have inspired revolts in Libya and as far away as Yemen and Oman. In Iran, where occasional protests also have broken out, authorities allegedly have thrown opposition leaders Mir-Hossein Mousavi and Mehdi Karroubi and their outspoken wives into the Heshmatieh prison, the reformist website Kaleme.com reported Monday. The four have not been heard from in days. The prison is under the authority of the military and is mostly used to lock up court-martialed soldiers and draft dodgers.

In Libya, foes of Kadafi are starting to set up what they describe as an alternative government based in Benghazi, the country's second-largest city.

Workers and supervisors at an oil and natural gas complex in Port Brega, on the coast close to the frontlines, said they were continuing to pump oil from wells in the interior but keeping it in the east to help support the effort to topple Kadafi.

On Monday, a rumor, later proved false, spread in Port Brega that Kadafi's forces were on the way from Surt, 200 miles to the west.

In Tripoli, Kadafi's supporters appear to be attempting to rally the population and international opinion to their side. As Libyans and visitors disembarked from a plane at the airport, they were greeted by a man in a gray Mitsubishi pickup truck honking the horn and shouting, "Long live Moammar!"

Just days earlier, reports from the capital said thousands of people had poured out of mosques after Friday prayers in defiance of Kadafi. Tripoli residents reached by telephone that day reported gunfire, and added that many who might be inclined to protest had hunkered down in their homes for safety. Some news reports quoted sources as saying dozens of people had died in the protests, which state television denied.

A quick tour of Tripoli late Monday by people close to the government showed general calm and a semblance of normality. Police and soldiers, some wearing green ribbons showing fealty to Kadafi, stopped drivers at multiple checkpoints in and around the city center. A trickle of cars continued to drive around the city well after dark.

In the capital's expansive Green Square, adjacent to the old city, several hundred people were honking horns, wrapping themselves in green banners, dancing and singing in support of the government.

"We are happy because we have survived the worst challenges," said Mohammad Tofani, a 38-year-old welder who was among the several hundred taking part in the festivities, which included live music. "Those people in Benghazi are using what is happening in Tunisia and Egypt to pursue their own interests."